Device for varying curvature of boat keels



Sept. 30, 19 52 P. BURCH 7 2,612,129

DEVICEFOR VARYING CURVATURE OF BOAT KEELS Filed Oct, 14, 1947 INVENTOR. LO REN P BURC ATTORNEY Patented Sept. 30, 1952 gag-612,129:

- 1 "Loren P. Burch, Aberdeen, Wash.

" Anselm pattern,194i.;'$eria1;1sa."mass" f 1 (c1. sis-ens) 'm 2 Claims.

lllhisginvention relates tobbatsand isparticularly related .to the keel of the .boat.

The primary object of the inventionris to .be abletolraisemr lower the keelmiclway thefstern andTbO-W. v f'I-Qfl In boat .language if thedkeel is raisedabove a straight line drawn from the stern to the bow it is known as placinga hogin't'hekeel. When the keel is.-lowered midway thezbowrand the stern beyond the straight line,:it;is :known as placing a rocker in the keel. With a hog in athe keel the bow of the boat .tends .toremainlnear the water while if a rocker is "put "in the "keel the bow of the boat .tends ';to :rise -a'b'ov.e the water line.

It is very desirable to have the bow of the boat rise above the water line for high speed operation and it is somewhat desirable to have the bow of the boat remain on the water line while operating with low power.

With my new and improved device for aligning keels of boats the keel can be aligned while the boat is being propelled through the water. which is a most desirable advantage.

A further object of the invention-is that during the life of a boat the alignment of the keel changes and with my new device this deformation can be corrected at will.

These and other incidental objects will be apparent in the drawings, specification and claims.

Referring to the drawings:

Figure -1 is a side view of a conventional boat having my new and improved device installed therein for aligning the keel.

Figure 2 is a sectional view of the boat, taken on line 2--2 of Figure l, more clearly illustrating my new and improved keel aligning device.

Figure 3 is a detail fragmentary view taken on line 3--3 of Figure 2.

Figure 4 is a modified form of construction adapted to certain types of boats.

Referring now to the drawing, the present invention is concerned with a boat which typically comprises a bottom 2 with a longitudinally extending centrally disposed keel I and having side walls 5 extending up to gunwales 6. The keel l extends from the bow 3 to the stern 4 of the boat, and except for a short length which is curved up to form the bow 3, the main length of the keel is normally substantially fiat and substantially parallel and aligned with a straight line which is identified in Figure 1 by a broken line A.

The present invention resides in means which is operable during operation of the boat, for adjusting the alignment of the fiat portion of the keel I relative to the line A. Normally, the keel l is aligned with the =lineiAbut irizsome circumstances jit is "desirable'to have the keel bowed upwardly 'so that the central 'porti'onof the keel is raised as "high as the level ot the broken line -;which is" known as hogging the keel.- "In other f circumstances, it is desirable to bow the "keel downwardly so that the central portion is new: ered to the'level of thebro'ken'line C,--which*--is known as putting-a rocker in the keel.

The selective alignment of the keel isaccom p'lished, in accordance with the present -inven-' tion, by "means of an athwartship *bri'd'ge span-'- ning 'the boat' and-an adjustablegmember,-specii1- cally a screw device, connected between said bridge and the keel substantially midway of the flat portion of the keel. As shown in Figures 1-3, a bridge I2 may be mounted athwartship on the gunwales 8 to span the boat, this bridge being substantially centrally of the boat. A turnbuckle screw is connected between the keel l and the bridge I 2, this screw comprising a turnbuckle l4 threadedly engaging two bolts I and ID. The bolt 1 is connected to the keel I, said bolt preferably extending through the keel with its head 9 embedded in the keel and the bolt clamped by a nut 8. The bolt I0 is connected to the bridge [2 by means of a block I I mounted on the bridge, the bolt [0 extending through the block II and being clamped by a nut l3.

Thus, to adjust the alignment of the keel I, the turnbuckle screw is selectively adjusted to be shortened or lengthened, this adjustment being accomplished by merely turning the turnbuckle M to thread it relative to the two bolts 1 and ID.

The turnbuckle I4 is adjusted by the operator of the boat and this adjustment may be effected while the boat is being propelled through the water. This is the outstanding feature of my invention, the ability to make the adjustment of the keel while the boat is being propelled, as this will give the desired result in the operation of the boat.

The foregoing modification is illustrated as embodying a cowl bridge that is built in during the construction of the boat. The present invention may be adapted to existing boats, or boats without cowls, by a preferred embodiment as shown in Figure 4. By this arrangement, a bridge l5 may be secured athwartship by bolts I! to the ribs I6 of the boat. The bridge l5 may be centrally slotted at 22 to provide two vertically spaced portions ISA and [5B that are respectively provided with vertical axially aligned bores [8A and |8B which are centrally of said bridge. A belt or screw [8 is secured to the keel I with its head .bolt and thereby bow the keel upwardly or downwardly.

In the operation of the boat, with my new and improved keel aligning device, the alignment of the keel, and consequently the elevation of the nose or how of the boat relative to the water line, may be selectively varied simply by adjusting the turnbuckle H or the hand wheel 2| while the boat is in operation.

I do not wish to be limited to the exact mechanical structure, as other mechanical embodi ments may be substituted still coming within the scope of my claims.

That which I claim as new, is: r

1. In a boat having a normally relatively fiat keel portion, a bridge spanning the bottom of said boat in its central portion and transversely above the keel portion, the central portion of said bridge being slotted to provide two vertically spaced portions, said bridge portions having vertical axially aligned bores therethrough centrally of said bridge, a screw fixed to the keel portion and extending upwardly through said bridge bores, and a nut on the screw and within the bridge slot for varying the relation of the screw to the bridge to bow the keel upwardly or downwardly relative to its normal fiat position.

2. In a boat having a normally relatively flat keel portion, a bridge spanning the bottom or the boat inits central portion and transversely of the flat keel portion, the central portion of said bridge being spaced above said keel portion, a single rigid member secured to said keel portion substantially intermediate the ends of said keel portion and engaging said bridge, and a manually operable means carried by said rigid member cooperating with said bridge for varying of the length of the rigid member to bow the keel portion upwardly or downwardly relative to its normal fiat position.

LOREN P. BURCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Yachting, January 1939, pp. 83 and 241. 

